June 2023 · Mississippi State University · Prototype
Soil-Moisture Logger for Remote Sensing
A prototype field logger for soil-moisture data. An ESP32 spends most of its time in deep sleep, wakes on an alarm from a DS3231 real-time clock, reads a TEROS 12 soil-moisture probe, saves the reading to an SD card and sends it out over a Zigbee radio.
How it works
- Controller
- ESP32 from the Hackster and DFRobot IoT starter kit
- Wake-up
- DS3231 alarm on an interrupt pin wakes the ESP32 from deep sleep
- Sensor
- TEROS 12 soil-moisture probe
- Storage
- Each reading appended to a file on an SD card
- Uplink
- Zigbee radio on a serial port
- Interval
- Every 30 minutes
The point of the design is battery life in the field: the board is awake only long enough to read, store and send one value, then goes back to deep sleep until the clock wakes it again.
This is an early prototype. The firmware is a first version and the Hackster write-up is still marked as under construction.
